The oil bag in a chicken is a gland located near the tail or bottom of the bird. This oil bag must be removed when the freshly-killed birds are processed for market. Although removal of the oil bag can be done manually with a knife, that procedure is labor-intensive and is not suited to modern poultry processing operations where each stage of poultry processing is mechanized to the greatest possible extent.
Machines intended for removing the oil bag are known in the prior art. Some examples of prior-art oil bag removing apparatus are found in U.S. Pat. Nos. 4,183,118; 4,532,676; 4,550,473; and 4,707,886. In the past, actual machines developed for removing oil bags of fowl moving along an overhead conveyor line has been relatively complex in construction and operation, increasing the costs of acquiring and operating that machinery. These machines generally move the birds in sequence past cutter elements of various kinds, and these cutter elements are positioned to sever and remove the oil bag as each bird reaches a predetermined position in relation to the cutter element. However, because the oil bag is located near the bottom of the bird, precise alignment of the bird with respect to the cutter element has proved necessary. If each bird is not aligned in an exact position relative to the cutter, part of the bird's tail may be cut off or the oil bag will not be completely removed. That unwanted cutting diminishes the value of the bird and is difficult to avoid with oil bag cutting apparatus of the prior art.